Subject: Summary: Calculation of J-coupling

From: "Carol Y.Y. Au" <[email-masked]>
Date: Wed, 3 Mar 1999 14:22:41 -0800 (PST)

Dear CCLers,

	Thanks for those who give advices to me. 
	
	In short, J-coupling can be calculated using Dalton.

	I would like to ask another question herein. 

	In the paper J. Chem. Phys. Vol. 71, No. 7, p.2896-2902, its states 
that the spin-spin coupling is related to the reduced spin-spin coupling 
constant (Kab), in which Kab is expressed in the second derivatives of the 
energy and is approximated using the finite perturbation method.  

	Kab = [E(La, Lb)-E(La, -Lb)]/2LaLb

where La and Lb are definite values of nuclear magnetic moments of 
nuclear a and nuclear b.

	Could anyone tell me how to modify Gaussian 94 in order to input 
the values of La and Lb for the calculation of Kab?     

Best wishes,

Carol Au
Dept. of Chem. CUHK
E-mail :[email-masked]
Phone  :(852) 2609 6167
Fax    :(852) 2603 5057

Original Posts: 
=============== 
> Dear CCLers,
> 
> 	I would like to know whether Gaussian can calculate the J-coupling 
> value of a molecule. Also, is there any program to calculate J-coupling? 
>
> 	Besides this, I am calculating the s-character of a molecule. I would 
> like to know whether it is meaningful to calculate it using DFT calculation.
>

Responds:
=========
From: "Dr. J. S. Tse" <[email-masked]>

	You can calculate the J-coupling using a public domina program called 
DALTON. Look into the website and search for DALTON.

	It is no program calculating the s-character using DFT.  It is as 
valid as using DFT for Mulliken population analysis - that is - if you 
believe that the KS orbitals have the same mening as HF orbitals.  Why 
not try HF?

    John
---------
From: Jerry C.C. Chan <[email-masked]>

	I am grateful to Profs Sauer, Ananikov and Joergen Aa. Jensen 
alerting me the availability of Dalton.

http://www.kjemi.uio.no/software/dalton/dalton.html

Cheers,
Jerry
---------
From: Doug Fox <[email-masked]>

No, Gaussian 98 cannot compute J coupling.  Spin-orbit coupling with the 
CASSCF method is only available for elements through Chlorine where LS 
coupling is used.

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